Scatty Doobin
Doobin refers to the act of smoking a 'doob' or 'spliff'. Scatty refers to the said doob being unsatisfactory or of bad quality. So scatty doobin means smoking a low quality spliff.
"Man, me and Tom were just scatty doobin all night."
"Unlucky mate, I got some high grade shit."
"Unlucky mate, I got some high grade shit."